In: Statistics and Probability
The expected distribution (from previous years) on an exam roughly follows a normal curve in which the highest scoring 2.5% of the students get As; the next highest scoring 14%, Bs; the next 67%, Cs; the next 14%, Ds; and the lowest 2.5%, Fs.
A class takes a test using a new grading system and 10 students get As, 34 get Bs, 140 get Cs, 10 get Ds, 6 get Fs. Can you conclude that the new system produces a different distribution of grades using .01 level?
Give: null, alternative, chi-square statistic, chi-square critical, decision, and conclusion.